PhysCasts: Time for Coffee
Hall, B. (Brenton) (2013)
A small electric immersion heater is used to heat 100 g of water for a cup of instant coffee. The heater is labelled "200 Watts" (it coverts electrical energy into thermal energy at this rate). Calculate the time required to ring all this water from 23.0 degrees C to 100 degrees C, ignoring heat losses.